U.S. patent application number 16/761742 was filed with the patent office on 2021-06-17 for implant and kit for the treatment and/or biological reconstruction of a bone defect.
The applicant listed for this patent is AESCULAP AG. Invention is credited to Wolfgang ABELE, Georg HETTICH, Silke KONIG.
Application Number | 20210177601 16/761742 |
Document ID | / |
Family ID | 1000005434337 |
Filed Date | 2021-06-17 |
United States Patent
Application |
20210177601 |
Kind Code |
A1 |
HETTICH; Georg ; et
al. |
June 17, 2021 |
IMPLANT AND KIT FOR THE TREATMENT AND/OR BIOLOGICAL RECONSTRUCTION
OF A BONE DEFECT
Abstract
An implant, in particular for the treatment and/or biological
reconstruction of a bone defect, includes osteoconductive
supporting bodies and a supporting sheath at least partially
surrounding the osteoconductive supporting bodies. The sheath can
be formed of a sheath material or can consist of a sheath material
that is soluble in water or in water-containing liquids. A kit and
method for the treatment and/or biological reconstruction of a bone
defect can utilize a sheath for osteoconductive supporting bodies
and a material for sheathing the osteoconductive supporting
bodies.
Inventors: |
HETTICH; Georg; (Tuttlingen,
DE) ; KONIG; Silke; (Rottweil, DE) ; ABELE;
Wolfgang; (Tuttlingen, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
AESCULAP AG |
Tuttlingen |
|
DE |
|
|
Family ID: |
1000005434337 |
Appl. No.: |
16/761742 |
Filed: |
October 26, 2018 |
PCT Filed: |
October 26, 2018 |
PCT NO: |
PCT/EP2018/079383 |
371 Date: |
May 5, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61L 27/20 20130101;
A61F 2002/30784 20130101; A61L 27/26 20130101; A61L 2300/236
20130101; A61F 2/30734 20130101; A61F 2002/30062 20130101; A61L
27/54 20130101; A61L 27/12 20130101; A61L 2430/02 20130101; A61L
27/18 20130101; A61F 2/2846 20130101; A61F 2002/30738 20130101;
A61L 27/34 20130101 |
International
Class: |
A61F 2/30 20060101
A61F002/30; A61F 2/28 20060101 A61F002/28; A61L 27/54 20060101
A61L027/54; A61L 27/20 20060101 A61L027/20; A61L 27/34 20060101
A61L027/34; A61L 27/18 20060101 A61L027/18; A61L 27/12 20060101
A61L027/12; A61L 27/26 20060101 A61L027/26 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 20, 2017 |
DE |
102017220710.8 |
Claims
1. An implant for the treatment and/or biological reconstruction of
a bone defect, comprising: osteoconductive supporting bodies; and a
sheath that at least partially surrounds the osteoconductive
supporting bodies, the sheath comprising a sheath material that is
soluble in water or in a water-containing liquid.
2. The implant according to claim 1, wherein the sheath material
comprises starch, amylose, amylopectin, dextran, methyl cellulose,
hydroxymethyl cellulose, ethyl cellulose, hydroxyethyl cellulose,
propyl cellulose, hydroxypropyl cellulose, butyl cellulose,
hydroxybutyl cellulose, hydroxyethylmethyl cellulose,
hydroxypropylmethyl cellulose, carboxymethyl cellulose, hyaluronic
acid, chondroitin-4-sulfate, chondroitin-6-sulfate, keratin
sulfate, alginic acid, heparin, heparan sulfate, chitosan, salts
thereof or mixtures thereof.
3. The implant according to claim 1, wherein the sheath material
comprises polyvinyl alcohol, polyethylene glycol, ethylene
oxide-propylene oxide copolymers (EO-PO copolymers), ethylene
oxide-propylene oxide block copolymers (EO-PO block copolymers),
acrylic acid homopolymers, acrylic acid copolymers,
polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers
or mixtures thereof.
4. The implant according to claim 1, wherein the sheath has a first
section and a second section that are designed differently.
5. The implant according to claim 4, wherein the first and second
sections differ from one another with regard to the solubility of
the sheath in water or in a water-containing liquid and/or with
regard to the thickness of the sheath and/or with regard to the
structure of the sheath.
6. The implant according to claim 4, wherein the first and second
sections differ from one another with regard to chemical
composition.
7. The implant according to claim 4, wherein the first section
comprises a sheath material that is more soluble in water or in a
water-containing liquid than the second section.
8. The implant according to claim 4, wherein the first section
comprises a less cross-linked sheath material that is soluble in
water or in a water-containing liquid than the second section.
9. The implant according to claim 4, wherein the first section
comprises a non-cross-linked sheath material that is soluble in
water or in a water-containing liquid, and the second section
comprises a cross-linked sheath material that is soluble in water
or in a water-containing liquid.
10. The implant according to claim 4, wherein the first section
comprises a higher proportion of a sheath material that is soluble
in water or in a water-containing liquid than the second
section.
11. The implant according to claim 4, wherein the first section
comprises a sheath material that is soluble in water or in a
water-containing liquid, and the second section comprises a sheath
material that is insoluble in water or in a water-containing
liquid.
12. The implant according to claim 4, wherein the first section has
a smaller thickness than the second section.
13. The implant according to claim 4, wherein the first section is
non-textile, and the second section is textile.
14. The implant according to claim 4, wherein the first section is
configured to face a bone in the implanted state, and the second
section is configured to face an artificial socket in the implanted
state.
15. The implant according to claim 4, wherein the osteoconductive
supporting bodies are present in isolated form and comprise
apatite, tricalcium phosphate, and/or biphasic calcium
phosphate.
16. The implant according to claim 15, wherein the osteoconductive
supporting bodies have a porosity of 1% to 50%.
17. The implant according to claim 15, wherein the osteoconductive
supporting bodies are non-porous.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the United States national phase entry
of International Application No. PCT/EP2018/079383, filed Oct. 26,
2018, and claims the benefit of priority of German application No.
10 2017 2207 10.8, filed Nov. 20, 2017. The contents of
International Application No. PCT/EP2018/079383 and German
application No. 10 2017 2207 10.8 are incorporated by reference
herein in their entireties.
FIELD
[0002] The invention relates to an implant and a kit for the
treatment and/or biological reconstruction of a bone defect, a
sheath for osteoconductive supporting bodies, the use of a material
that is soluble in water or in a water-containing liquid for
producing a sheath for osteoconductive supporting bodies and a
method for the treatment and/or biological reconstruction of a bone
defect.
BACKGROUND
[0003] Large bone defects on the acetabulum are a serious problem
during revision surgery on the hip joint. Hip revision surgery has
three main goals.
[0004] First, the original joint center is to be restored.
[0005] Furthermore, a stable fixation of an implant used to treat
an acetabular defect is sought, a distinction being made between
so-called primary stability and so-called secondary stability.
[0006] Primary stability is understood to mean the fixation of the
implant based on friction or fastening elements, such as bone
screws, in the first weeks after an operation. Secondary stability
is understood to mean the fixation of the implant based on osseous
growths. Secondary stability usually sets in about a month after a
surgical procedure and can last up to several years.
[0007] Finally, a so-called biological reconstruction of the
osseous defect is sought. A biological reconstruction is understood
to mean the penetration and/or the reconstruction of a bone defect
with the body's own bone.
[0008] Acetabular defects are referred to as "contained" defects if
vital patient bone and an inserted hip socket completely enclose
the defect. In contrast, acetabular defects are referred to as
uncontained defects if an inserted hip socket does not completely
enclose the defect, i.e. uncontained portions remain.
[0009] In practice, the so-called "Impaction Bone Grafting"
technique has become established for the treatment of contained
acetabular defects. In this technique, pieces of bone (cancellous
bone) approximately 0.5 cm in size are prepared from an allogeneic
bone material (femoral head) and compacted into the bone defect
using a suitable instrument. Using this technique, the acetabular
defect can be biologically reconstructed and the center of rotation
restored. However, allogeneic bone chips pose a risk of infection
despite thermal treatment. Another disadvantage is the cost of
producing allogeneic bone chips, which have increased significantly
due to increased regulatory requirements. After all,
intra-operative handling is extremely complicated and
time-consuming. The human femoral head, from which the bone chips
are produced, must be thawed and crushed during the operation. The
chips produced in this way are irregular in shape and some surgical
experience is required to use the chips properly.
[0010] Another approach to treating bone defects is artificial bone
replacement materials, especially those based on calcium phosphate
materials. A disadvantage of artificial bone replacement materials
is often their limited mechanical resilience, i.e. the primary
stability that can be achieved with them is limited. Another
disadvantage is the risk of the bone replacement materials being
degraded or absorbed without bone growth and consequently without
achieving secondary stability.
[0011] U.S. Pat. No. 8,562,613 B2 discloses a kit for the treatment
of bone defects with a mixture of an osteoconductive material and
an osteoinductive material, and a porous container.
[0012] The subject matter of EP 0 764 008 B1 is a device for use in
the stabilization of a spinal movement segment with a flexible bag,
wherein the bag can contain a biological filling material for
promoting bone or fiber growth.
[0013] EP 1 408 888 B1 discloses a system for correcting vertebral
compression fractures, which comprises a porous bag and a filling
tool, the filling tool being designed to inject a bone filling
material under pressure into the porous bag.
[0014] An implantable container is known from WO 2012/061024 A1,
which contains at least partially demineralized and osteoinductive
bone particles.
[0015] The publication "Bone Regeneration by the Combined Use of
Tetrapod-Shaped Calcium Phosphate Granules with Basic Fibroblast
Growth Factor-Binding Ion Complex Gel in Canine Segmental Radial
Defects (J. Vet. Med. Sci. 76(7):955-961, 2014)" by Honnami et al.
deals with a combination of tetrapod-shaped granules of
alpha-tricalcium phosphate and an osteoinductive gel.
SUMMARY
[0016] It is the object of the invention to provide an implant
which is suitable for the treatment and/or biological
reconstruction of a bone defect, in particular periprosthetic bone
defect such as an acetabular defect, and which avoids or at least
partially avoids the disadvantages mentioned above, in particular
in connection with a hip revision operation. The implant should in
particular optimize the achievement of primary stability and/or
secondary stability and/or biological reconstruction and enable
simple and low-complication handling.
[0017] Furthermore, it is an object of the invention to provide a
kit for the treatment and/or biological reconstruction of a bone
defect, a sheath for osteoconductive supporting bodies, the use of
a material for producing such a sheath and a method for the
treatment and/or biological reconstruction of a bone defect.
[0018] These objects are achieved by an implant and by a kit
disclosed in the description, a sheath disclosed in the
description, a use disclosed in the description and by a method for
the treatment and/or biological reconstruction of a bone defect
disclosed in the description.
[0019] According to a first aspect, the invention relates to an
implant, preferably for the treatment and/or biological
reconstruction, in particular lining and/or sealing and/or relining
and/or at least partially filling, a bone defect.
[0020] For the purposes of the present invention, the implant can
also be referred to as bone replacement material.
[0021] The implant comprises the following: [0022] osteoconductive
supporting bodies and [0023] a sheath that at least partially,
preferably completely, surrounds the osteoconductive supporting
bodies.
[0024] The sheath is particularly characterized by the fact that it
comprises a sheath material or consists of a sheath material that
is soluble in water or in a water-containing liquid. Such a sheath
material is also abbreviated below as a soluble sheath
material.
[0025] The sheath can be a film, a fleece, a nonwoven material, a
mesh or a textile fabric, in particular a woven, braided or knitted
fabric, such as a knitted or crocheted mesh. The sheath can be
produced or manufactured in particular by extrusion, by blow
molding, by injection molding, by a compression molding process or
by an additive process. The sheath can further comprise
monofilament thread material and/or multifilament thread material
or consist of monofilament thread material and/or multifilament
thread material.
[0026] For the purposes of the present invention, the term "bone
defect" shall be understood to mean a bone area affected by loss of
bone tissue, in particular joint bone tissue, preferably hip or
knee joint bone tissue, or bone area affected by vertebral body
tissue, in particular joint bone area, preferably hip joint or knee
joint bone area, or vertebral body area. The bone loss can be the
result of a bone fracture, a bone trauma, a bone disease such as
tumor disease or a surgical intervention/reintervention, especially
a revision after total hip or knee arthroplasty. Preferably, for
the purposes of the present invention, the term "bone defect" shall
be understood to mean a periprosthetic bone defect, i.e. a bone
area affected by periprosthetic bone tissue loss, in particular due
to mechanical overload and/or wear-induced osteolysis and/or
implant migration.
[0027] The bone defect is preferably a joint bone defect, in
particular a knee joint bone defect or a hip joint bone defect,
preferably an acetabular defect, in particular a contained or
uncontained acetabular defect.
[0028] Furthermore, for the purposes of the present invention, the
term "bone defect" can mean a human bone defect or an animal bone
defect.
[0029] For the purposes of the present invention, the term "animal
bone defect" shall be understood to mean the bone defect of a
non-human mammal, such as, for example, a horse, cow, goat, sheep,
pig or a rodent, such as, for example, a rabbit, rat or mouse.
[0030] For the purposes of the present invention, the term
"supporting body" shall be understood to mean bodies, in particular
regularly and/or irregularly molded bodies, which are designed to
withstand forces normally occurring in a bone defect to be treated
and/or biologically reconstructed without deformation or
destruction, but at least without substantial deformation or
destruction and therefore to take on load-bearing functions. For
this reason, for the purposes of the present invention, the
supporting bodies can also be referred to as osteoconductive,
load-bearing supporting bodies.
[0031] For the purposes of the present invention, the term
"osteoconductive" used in connection with the supporting bodies
shall be understood to mean the ability of the supporting bodies to
form a three-dimensional structure, in particular a lead structure,
or a three-dimensional matrix, in particular a lead matrix, which
promotes ingrowth of bone tissue, in particular new bone
tissue.
[0032] For the purposes of the present invention, the term
"degradable in vivo" relates to a substance or a material which can
be metabolized in a human or animal body, in particular by the
action of enzymes. The breakdown of the substance or material can
proceed completely all the way to mineralization, i.e. the release
of chemical elements and their incorporation into inorganic
compounds, such as, for example, carbon dioxide and/or oxygen
and/or ammonia, or remain at the level of non-degradable
intermediate or transformation products.
[0033] For the purposes of the present invention, the term "animal
body" shall be understood to mean the body of a non-human mammal,
such as, for example, a horse, cow, goat, sheep, pig or rodent,
such as a rabbit, rat or mouse.
[0034] For the purposes of the present invention, the term
"absorbable in vivo" refers to a substance or a material which can
be absorbed in a human or animal body by living cells or living
tissue, such as, for example, kidneys, without degradation or
significant degradation of the substance or material taking
place.
[0035] For the purposes of the present invention, the term "sheath"
shall be understood to mean a structure or construct which is
designed to partially, preferably completely, surround or enclose
(at least) the osteoconductive supporting bodies. For this purpose,
the sheath preferably has a void which can be filled or is filled
with (at least) the osteoconductive supporting bodies at least
partially, preferably only partially.
[0036] For the purposes of the present invention, the term "sheath
material" shall be understood to mean a material which is part of
the sheath and in particular is involved in the construction of the
sheath. Depending on its solubility in water or in a
water-containing liquid, the sheath material can be the main
component or even the exclusive component of the sheath or only a
secondary component, in particular in the sense of an additive.
[0037] For the purposes of the present invention, the term
"water-containing liquid" shall be understood to mean an aqueous
liquid, i.e. a liquid which contains water, the liquid optionally
containing further substances, such as salts, proteins,
polysaccharides, lipids, blood components or mixtures thereof,
and/or cells. Accordingly, the water-containing liquid for the
purposes of the present invention can be, for example, an aqueous
dispersion, an aqueous solution such as aqueous salt solution, an
aqueous suspension or a body fluid. For the purposes of the present
invention, the term "water-containing liquid" shall preferably be
understood to mean an aqueous solution or a body fluid, such as,
for example, blood and/or tissue fluid and/or lymph fluid. It is
further preferred that the water-containing liquid for the purposes
of the present invention is free from organic solvents.
[0038] The present invention is characterized in particular by the
following advantages: [0039] The sheath serves particularly
advantageously as an insertion aid for the osteoconductive
supporting bodies, without representing a barrier for ingrowing
bone tissue and therefore for a biological reconstruction of the
osseous defect. The soluble sheath material particularly
advantageously creates the prerequisite that the sheath at least
partially dissolves after the implant has been placed in a bone
defect, so that, with a good healing process, ingrowing bone tissue
can penetrate the osteoconductive supporting bodies, whereby the
latter can be integrated into the bone. As a result, a biological
reconstruction and consequently a reduction in the size of the
osseous defect is possible even in the case of osteoconductive
supporting bodies that cannot be degraded in vivo or can only be
degraded very slowly or are absorbable in vivo.
[0040] In the event of missing or poor bone growth, the
osteoconductive supporting bodies are preferably retained and thus
contribute to secondary stability. Thus, secondary stability can
preferably be ensured, regardless of whether or not there is a
built-up of bone tissue in the osteoconductive supporting bodies
after implantation. This is particularly advantageous with regard
to the care of older patients, in whom bone growth often no longer
takes place or only occurs slightly. [0041] Another advantage of
the sheath is that it fixes the osteoconductive supporting body in
place. In this way, an uncontrolled introduction of the supporting
bodies into the bone defect can be avoided in a particularly
advantageous manner. [0042] A further advantage of the sheath is,
in particular, that the osteoconductive supporting body can be
compacted, in particular impacted, without an uncontrolled
distribution of the osteoconductive supporting body within the bone
defect during compacting, in particular impacting.
[0043] The sheath also offers the advantage of simple and, in
particular, quick handling during a surgical procedure. [0044]
Another advantage is that the osteoconductive supporting bodies, in
particular in the form of a loose or isolated bulk material, can be
converted into a compacted, preferably impacted (clamped or wedged)
state and in this state they can function as a lead structure for
the ingrowth of bone tissue, in particular new bone tissue. [0045]
Another advantage is that the implant can, particularly when the
osteoconductive supporting bodies are in a compacted, in particular
impacted, state, be loaded permanently and, above all,
homogeneously. A homogeneous implant load is a basic requirement
for bone growth.
[0046] For example, the implant with compacted, in particular
impacted, osteoconductive supporting bodies can be permanently
subjected to a pressure load of up to 5 MPa. A structure produced
by compacting, in particular impacting, and constructed by the
osteoconductive supporting bodies can, with particular advantage,
have an elastic deformation, in particular from 5% to 15%, and a
low modulus of elasticity, in particular from 50 MPa to 300
MPa.
[0047] The osteoconductive supporting bodies preferably have at
least one size or dimension in a size range from 0.5 mm to 5 mm, in
particular 0.1 mm to 3 mm, preferably 1 mm to 2 mm. The at least
one size or dimension can be in particular the height and/or width
(thickness) and/or length and/or the diameter, in particular the
average diameter, of the osteoconductive supporting bodies.
[0048] In a further embodiment, the osteoconductive supporting
bodies are moveable relative to one another, in particular are
displaceable relative to one another.
[0049] In a further embodiment, the osteoconductive supporting
bodies can be impacted, i.e. mutually clamped or mutually
wedged.
[0050] In a further embodiment, the osteoconductive supporting
bodies, are mutually clamped or mutually wedged.
[0051] In a further embodiment, the osteoconductive supporting
bodies can, preferably by impacting, be converted into a
three-dimensional structure or matrix, in particular having voids
and/or spaces, or are present in such a structure or matrix. For
the purposes of the present invention such a structure or matrix
can also be referred to as an osteoconductive lead structure or
osteoconductive lead matrix.
[0052] The voids or spaces in the structure or matrix can have a
diameter of 0.1 mm to 1.2 mm, in particular 0.2 mm to 1 mm,
preferably 0.3 mm to 0.8 mm. [0053] In contrast to generic
implants, in particular metallic augmentations, in which only
spaces at the implant edge zones are mechanically stressed,
existing voids and/or spaces present in a compacted state of the
osteoconductive supporting bodies within a complete defect filling,
i.e. homogeneous, can be mechanically loaded (micro movements) due
to a low modulus of elasticity. This in turn stimulates and/or
reinforces bone growth, in particular new bone formation. Overall,
a homogeneous ossification of the entire bone defect can be
achieved.
[0054] In a configuration of the invention, the solubility of the
sheath material is based on a physical dissolution process, i.e.
the sheath material is soluble in water or in a water-containing
liquid without degradation or other destruction.
[0055] In a further configuration of the invention, the solubility
of the sheath material is based on degradation, in particular
hydrolysis, such as, for example, enzyme-catalyzed hydrolysis, of
the soluble sheath material.
[0056] In a further configuration of the invention, the soluble
sheath material is soluble in water or in a water-containing
liquid, in particular body fluid, for a period of 1 second to 72
hours, in particular 1 minute to 1 hour, preferably 2 minutes to 20
minutes.
[0057] In a further configuration of the invention, the soluble
sheath material comprises or consists of a polysaccharide. The
polysaccharide can be in particular a mucopolysaccharide and/or a
cellulose derivative, in particular an alkyl cellulose and/or
hydroxyalkyl cellulose. The polysaccharide is preferably selected
from the group consisting of starch, amylose, amylopectin, dextran,
methyl cellulose, hydroxymethyl cellulose, ethyl cellulose,
hydroxyethyl cellulose, propyl cellulose, hydroxypropyl cellulose,
butyl cellulose, hydroxybutyl cellulose, hydroxyethylmethyl
cellulose, hydroxypropylmethyl cellulose, carboxymethyl cellulose,
hyaluronic acid, chondroitin-4-sulfate, chondroitin-6-sulfate,
keratin sulfate, alginic acid, heparin, heparan sulfate, chitosan,
salts thereof or mixtures thereof.
[0058] In a further configuration of the invention, the soluble
sheath material comprises a synthetic polymer or consists of such a
polymer. The synthetic polymer is preferably selected from the
group consisting of polyvinyl alcohol, polyethylene glycol,
ethylene oxide-propylene oxide copolymers (EO-PO copolymers),
ethylene oxide-propylene oxide block copolymers (EO-PO block
copolymers), acrylic acid homopolymers, acrylic acid copolymers,
polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers
or mixtures thereof.
[0059] The polyvinyl alcohol mentioned in the previous paragraph
can be in particular a so-called low molecular weight polyvinyl
alcohol, i.e. a polyvinyl alcohol with an average molecular weight
of 10,000 to 30,000 and/or a so-called high molecular weight
polyvinyl alcohol, i.e. a polyvinyl alcohol with an average
molecular weight of 50,000 to 250,000.
[0060] In a further configuration of the invention, the soluble
sheath material comprises a low molecular weight polyvinyl alcohol,
i.e. a polyvinyl alcohol with an average molecular weight of 10,000
to 30,000 and/or a high molecular weight polyvinyl alcohol, i.e. a
polyvinyl alcohol with an average molecular weight of 50,000 to
250,000, and also a polysaccharide, in particular a carboxyalkyl
cellulose, preferably carboxymethyl cellulose.
[0061] In a further configuration of the invention, the soluble
sheath material comprises a mixture of a polysaccharide and a
synthetic polymer or consists of such a mixture. With regard to a
suitable polysaccharide and synthetic polymer, reference is made to
the polysaccharides and synthetic polymers described in the
previous paragraphs.
[0062] The soluble sheath material can furthermore have a
proportion of 0.1% by weight to 100% by weight, in particular 5% by
weight to 100% by weight, preferably 90% by weight to 100% by
weight, based on the total weight of the sheath. The higher the
proportion of the soluble sheath material, the more completely the
sheath can be dissolved in water or in a water-containing liquid.
The solubility of the sheath can thus be controlled with particular
advantage via the proportion of the soluble sheath material.
[0063] In a further configuration of the invention, the soluble
sheath material is at least partially, in particular only partially
or completely, crosslinked. The soluble sheath material can be
chemically and/or physically cross-linked. For example, the sheath
material can be crosslinked by a chemical crosslinking agent, in
particular selected from the group consisting of formaldehyde,
dialdehyde such as glutaraldehyde, polyaldehydes, diisocyanates,
dicarbodiimides or mixtures thereof. The chemical crosslinking
agent can have a proportion of 0.1% by weight to 20% by weight, in
particular 1% by weight to 10% by weight, preferably 2% by weight
to 5% by weight, based on the total weight of the sheath.
Alternatively or in combination, the sheath material can be
crosslinked by radiation, in particular gamma radiation, and/or by
freeze-thaw cycles. Crosslinking, in particular the type and/or the
degree of crosslinking, or a lack of crosslinking, can also be used
to control the solubility of the sheath material and thus the
sheath in water or in a water-containing liquid with particular
advantage, with crosslinking generally reducing the solubility or
increasing in the dissolution time.
[0064] In a further configuration of the invention, the sheath is
free of a crosslinking agent.
[0065] In a further configuration of the invention, the sheath
further comprises a sheath material which is insoluble in water or
in a water-containing liquid. Such a sheath material is also
abbreviated below as an insoluble sheath material.
[0066] The insoluble sheath material is preferably a polymer,
especially a hydrophobic polymer.
[0067] The polymer is preferably selected from the group consisting
of polyolefin, polyester, polyamide, polyurethane such as
thermoplastic polyurethane, elastomer, polyimide, polyether ketone,
polyether ether ketone, fluorocarbon, perfluorocarbon or mixtures
thereof.
[0068] The polyolefin can be selected from the group consisting of
polyethylene, polypropylene, polyacrylate, polymethacrylate,
polymethyl methacrylate, polyvinylidene chloride, polyvinylidene
fluoride, polytetrafluoroethylene, polytetrafluoropropylene,
polyhexafluoropropylene, copolymers thereof or mixtures
thereof.
[0069] The polyethylene may be in particular low density
polyethylene, medium density polyethylene, high density
polyethylene, ultra high molecular weight polyethylene, a copolymer
thereof or mixtures thereof. In particular, the polyester can be
selected from the group consisting of polyethylene terephthalate,
polypropylene terephthalate, polybutylene terephthalate, copolymers
thereof or mixtures thereof.
[0070] In particular, the polyamide can be selected from the group
consisting of polyamide 6 (polyamide from caprolactam), polyamide
46 (polyamide from tetramethylene diamine and adipic acid),
polyamide 6.6 (polyamide from hexamethylene diamine and adipic
acid), polyamide 69 (polyamide from hexamethylene diamine and
azelaic acid), polyamide 6/12 (polyamide from hexamethylene diamine
and dodecanedioic acid), polyamide 1010 (polyamide from
1,10-decanediamine and sebacic acid), polyamide 11 (polyamide from
alpha-aminoundecanoic acid), polyamide 12 (polyamide from
laurolactam), polyamide 1212 (polyamide from dodecanediamine and
dodecanedioic acid), silk, copolymers thereof or mixtures
thereof.
[0071] The insoluble sheath material can have a proportion of 0.1%
by weight to 99% by weight, in particular 0.1% by weight to 50% by
weight, preferably 0.1% by weight to 1% by weight, based on the
total weight of the sheath. The solubility of the sheath can also
be deliberately influenced by the proportion of an optionally
present insoluble sheath material. A proportion of an insoluble
sheath material reduces the solubility of the sheath overall.
[0072] Furthermore, the insoluble sheath material can be present,
in particular, in the form of an additive of the sheath.
[0073] For the purposes of the present invention, the term
"additive" shall be understood to mean an admixture which has a
maximum proportion of 49% by weight, in particular 0.1 to 40% by
weight, preferably 2% by weight to 20% by weight, based on the
total weight of the sheath.
[0074] In a further configuration of the invention, the sheath is
free of a sheath material that is insoluble in water or in a
water-containing liquid.
[0075] In a further configuration of the invention, the sheath or a
section of the sheath has a thickness of 10 .mu.m to 1 mm, in
particular 20 .mu.m to 800 .mu.m, preferably 30 .mu.m to 300 .mu.m.
In particular, the sheath can have a uniform thickness or, as will
be explained in more detail below, a non-uniform thickness, i.e.
have an irregular thickness.
[0076] In a further configuration of the invention, the sheath or a
section of the sheath is designed in the form of a film. In other
words, in a further configuration of the invention, the sheath or a
section thereof is in the form of a film. A film-shaped section of
the sheath preferably comprises a sheath material that is soluble
in water or in a water-containing liquid or consists of such a
sheath material. Furthermore, it is preferred if a film-shaped
section of the sheath is arranged facing the bone in the implanted
state. With regard to suitable soluble sheath materials, reference
is made to the description above.
[0077] For the purposes of the present invention, the term
"film-shaped" or "film" used in the context of the sheath is
intended to define a sheath that preferably has a thickness of 10
.mu.m to 1 mm, in particular 20 .mu.m to 800 .mu.m, preferably 30
.mu.m to 300 .mu.m. Such a thin configuration of the sheath is
particularly advantageous with regard to the quickest possible
solubility of the sheath material and thus of the sheath.
[0078] In a further configuration of the invention, a section of
the sheath is textile, in particular mesh-shaped, i.e. in the form
of a mesh. The section preferably comprises a sheath material which
is insoluble in water or in a water-containing liquid or consists
of such a sheath material. Furthermore, it is preferred if, in the
implanted state, the section is arranged facing an artificial joint
socket, in particular an artificial hip joint socket. With regard
to suitable insoluble sheath materials, reference is made to the
description above.
[0079] For the purposes of the present invention, the term
"mesh-shaped" or "mesh" shall be understood to mean the shape of a
textile fabric or a textile fabric which preferably has regular
meshes or openings, the meshes or openings, for example, can be
rhombic, square or hexagonal. In particular, the term "mesh-shaped"
or "mesh" shall be understood to mean the shape of a braided or
knitted fabric or a braided or knitted fabric.
[0080] In a further configuration of the invention, the sheath has
sections, in particular a first section and a second section, which
are designed differently. This makes it possible in particular to
achieve a directional and/or side-dependent solubility of the
sheath in water or in a water-containing liquid.
[0081] In a further configuration of the invention, the sections
differ from one another with regard to the solubility of the sheath
in water or in a water-containing liquid and/or with regard to the
thickness of the sheath and/or with regard to the structure of the
sheath.
[0082] In a further configuration of the invention, the sections
differ from one another with regard to the chemical composition, in
particular with regard to crosslinking of the sheath material. With
regard to the chemical composition and possible crosslinking,
reference is made to the (soluble and insoluble) sheath materials
described so far and to the crosslinking options described so
far.
[0083] In particular, the sections can differ from one another with
regard to the type of crosslinking and/or the degree of
crosslinking. For example, the sections can differ from one another
with regard to a chemical crosslinking agent and/or a physical
crosslinking. With regard to suitable chemical crosslinking agents
and physical crosslinking, reference is made to the previous
statements made in connection with an optional crosslinking of the
soluble sheath material.
[0084] In a further configuration of the invention, the first
section comprises a sheath material that is better or faster
soluble in water or in a water-containing liquid or consists of
such a sheath material, than the second section. In the implanted
state, the first section is preferably arranged facing the bone,
whereas, in the implanted state, the second section of the sheath
is arranged facing an artificial joint socket, in particular an
artificial hip joint socket. As a result, it can be achieved in a
particularly advantageous manner that the sheath initially only
dissolves in the area with respect to which bone tissue can be
expected to grow in, whereas the remaining part of the sheath is
characterized by a comparatively higher resistance to water or a
water-containing liquid, so that a partial integrity of the sheath
can be maintained at least during an initial phase after
implantation. With regard to suitable sheath materials, reference
is made to the description above.
[0085] In a further configuration of the invention, the first
section comprises a weaker crosslinked sheath material that is
soluble in water or in a water-containing liquid or consists of
such a sheath material, than the second section. In other words, in
a further configuration of the invention, the first section
comprises a sheath material which is soluble in water or in a
water-containing liquid and has a lower degree of crosslinking, or
consists of such a sheath material, than the second section. In the
implanted state, the first section is preferably arranged facing
the bone, whereas, in the implanted state, the second section of
the sheath is arranged facing an artificial joint socket, in
particular an artificial hip joint socket. With regard to suitable
sheath materials, reference is made to the description above.
[0086] In a further configuration of the invention, the first
section comprises a non-crosslinked sheath material that is soluble
in water or in a water-containing liquid, or consists of such a
sheath material, whereas the second section comprises a crosslinked
sheath material that is soluble in water or in a water-containing
liquid or consists of such a sheath material. In the implanted
state, the first section is preferably arranged facing the bone,
whereas, in the implanted state, the second section of the sheath
is arranged facing an artificial joint socket, in particular an
artificial hip joint socket. With regard to suitable sheath
materials, reference is made to the description above.
[0087] In a further configuration of the invention, the first
section comprises a higher proportion of a sheath material that is
soluble in water or in a water-containing liquid, than the second
section. In the implanted state, the first section is preferably
arranged facing the bone, whereas, in the implanted state, the
second section of the sheath is arranged facing an artificial joint
socket, in particular an artificial hip joint socket. With regard
to suitable sheath materials, reference is made to the description
above.
[0088] In a further configuration of the invention, the first
section comprises a sheath material that is soluble in water or in
a water-containing liquid or consists of such a sheath material,
whereas the second section comprises a sheath material that is
insoluble in water or in a water-containing liquid or consists of
such a sheath material. In the implanted state, the first section
is preferably arranged facing the bone, whereas, in the implanted
state, the second section of the sheath is arranged facing an
artificial joint socket, in particular an artificial hip joint
socket. With regard to suitable sheath materials, reference is made
to the description above.
[0089] In a further configuration of the invention, the first
section has a smaller thickness than the second section. In the
implanted state, the first section is preferably arranged facing
the bone, whereas, in the implanted state, the second section of
the sheath is arranged facing an artificial joint socket, in
particular an artificial hip joint socket.
[0090] In a further configuration of the invention, the first
section is not textile-shaped, in particular film-shaped, and the
second section is textile-shaped, in particular mesh-shaped, i.e.
in the form of a mesh. In the implanted state the first section is
preferably arranged facing the bone, whereas, in the implanted
state, the second section of the sheath is arranged facing an
artificial joint socket, in particular an artificial hip joint
socket.
[0091] In a further configuration of the invention, the sheath is
designed to be dimensionally stable, in particular adapted to a
bone defect.
[0092] In a further configuration of the invention, the sheath is
only partially filled with the osteoconductive supporting bodies.
For example, a void volume defined by the sheath can only be filled
to 50% to 80% with the osteoconductive supporting bodies. In this
way, a sheath that can be shaped and can therefore be adapted to
the bone defect to be treated and/or biologically reconstructed can
be realized with particular advantage.
[0093] In a further configuration of the invention, the
osteoconductive supporting bodies are isolated osteoconductive
supporting bodies. In other words, in a further configuration of
the invention, the osteoconductive supporting bodies are present in
isolated form, i.e. in the form of individual supporting bodies,
for example in the form of a bulk material, as will be explained in
more detail below.
[0094] In a further configuration of the invention, the
osteoconductive supporting bodies comprise apatite and/or
tricalcium phosphate or consist of apatite and/or tricalcium
phosphate. The osteoconductive supporting bodies can each comprise
a proportion of apatite from 0.1% by weight to 100% by weight.
Furthermore, the osteoconductive supporting bodies can each
comprise a proportion of tricalcium phosphate from 0.1% by weight
to 100% by weight.
[0095] The apatite is preferably an apatite that cannot be degraded
in vivo or is not absorbable in vivo. As a result, sufficient
secondary stability can be achieved even in patients for whom
(sufficient) bone growth can no longer be expected. This is
particularly advantageous with regard to the treatment of bone
defects in older patients.
[0096] Alternatively, the apatite can be an apatite that can be
degraded in vivo or is absorbable in vivo, preferably an apatite
that is slowly degradable in vivo or slowly absorbable in vivo. In
particular, the apatite can have an in vivo degradation time or an
in vivo absorption time of 6 months to 30 years, in particular 1
year to 20 years, preferably 4 years to 10 years. The degradation
or absorption times provided in this paragraph are particularly
advantageous with regard to the treatment of patients with slow or
even missing bone growth.
[0097] The apatite can also be present in particular in crystalline
form. A high degree of strength can be achieved by a high
crystallinity. Due to a low crystallinity, good and/or quick
degradability can be achieved.
[0098] Furthermore, the apatite can be a microcrystalline apatite,
i.e. an apatite with crystallites which have at least one size or
dimension in the micrometer range, in particular in a range>0.5
.mu.m, in particular 0.6 .mu.m to 500 .mu.m, preferably 0.6 .mu.m
to 100 .mu.m. The at least one size or dimension can be the length
and/or width (thickness or height) and/or the diameter, especially
the average diameter, of the crystallites.
[0099] Basically, the apatite can also be a macrocrystalline
apatite.
[0100] Furthermore, the apatite can be a nanocrystalline apatite,
i.e. an apatite with crystallites which have at least one size or
dimension in the nanometer range, in particular in a range from 0.1
nm to 500 nm, preferably 0.1 nm to 100 nm. The at least one size or
dimension can be the length and/or width (thickness or height)
and/or the diameter, especially the average diameter, of the
crystallites.
[0101] Furthermore, the apatite can be present in an amorphous
form. This enables particularly good and/or rapid absorption to be
achieved.
[0102] Furthermore, the apatite can be a phase-pure apatite. The
term "phase-pure" shall be understood to mean in particular
phase-pure in the sense of a relevant regulation, preferably
according to ASTM F1185.
[0103] Furthermore, the apatite can have a porosity of less than
50%, in particular less than 20%, preferably less than 15%. Due to
a low porosity, high mechanical stability can be achieved.
[0104] Furthermore, the apatite cannot be porous.
[0105] Furthermore, the osteoconductive supporting bodies can
comprise a mixture of porous apatites and/or apatites with
different porosity and/or non-porous apatites or consist of such a
mixture, in particular if the supporting bodies are produced by an
additive manufacturing process.
[0106] Furthermore, the apatite can be naturally occurring apatite
or an apatite obtained from natural apatite.
[0107] Furthermore, the apatite can be a synthetic, i.e. man-made
or artificial apatite.
[0108] The apatite is preferably selected from the group consisting
of hydroxylapatite, fluorapatite, chlorapatite,
carbonate-fluorapatite or mixtures thereof.
[0109] Particularly preferably, the apatite is hydroxylapatite. For
example, the hydroxyapatite can be a fully synthetic,
nanocrystalline and phase-pure hydroxyapatite. Such a
hydroxyapatite is commercially available, for example under the
registered trademark Ostim.RTM..
[0110] The apatite and the tricalcium phosphate can also be present
as a biphasic mixture. The biphasic structure is advantageous
because the bone cells can grow in and the material is gradually
replaced. The apatite and/or the tricalcium phosphate and/or the
biphasic calcium phosphate have a porosity of 1% to 50%, in
particular 5% to 20%, preferably 10% to 15%.
[0111] Furthermore, the apatite can be a sintered apatite.
[0112] The sintered apatite is preferably selected from the group
consisting of sintered hydroxyapatite, sintered fluorapatite,
sintered chlorapatite, sintered carbonate-fluorapatite or mixtures
thereof.
[0113] In a further configuration of the invention, the
osteoconductive supporting bodies comprise tricalcium phosphate or
consist of tricalcium phosphate.
[0114] The tricalcium phosphate is preferably a tricalcium
phosphate that is not degradable in vivo or is not absorbable in
vivo. As a result, sufficient secondary stability can be achieved
even in patients for whom (sufficient) bone growth can no longer be
expected. This is particularly advantageous with regard to the
treatment of bone defects in older patients.
[0115] Alternatively, the tricalcium phosphate can be a tricalcium
phosphate that is degradable in vivo or absorbable in vivo,
preferably a tricalcium phosphate that is slowly degradable in vivo
or slowly absorbable in vivo. In particular, the tricalcium
phosphate can have an in vivo degradation time or an in vivo
absorption time of 1 month to 15 years, in particular 6 months to
10 years, preferably 1 year to 5 years. The degradation or
absorption times provided in this paragraph are particularly
advantageous with regard to the treatment of patients with slow
bone growth.
[0116] The tricalcium phosphate can also be present in crystalline
form. A high degree of strength can be achieved by a high
crystallinity. Due to a low crystallinity, good and/or quick
degradability can be achieved. Preferably the tricalcium phosphate
has a crystallinity from 50% to 99%, in particular 75% to 95%.
[0117] Furthermore, the tricalcium phosphate can be
microcrystalline tricalcium phosphate, i.e. to tricalcium phosphate
with crystallites which have at least one size or dimension in the
micrometer range, in particular in a range>0.5 .mu.m, in
particular 0.6 .mu.m to 500 .mu.m, preferably 0.6 .mu.m to 100
.mu.m. The at least one size or dimension can be the length and/or
width (thickness or height) and/or the diameter, especially the
average diameter, of the crystallites.
[0118] Basically, the tricalcium phosphate can also be a
macrocrystalline tricalcium phosphate.
[0119] Furthermore, the tricalcium phosphate can be nanocrystalline
tricalcium phosphate, i.e. to tricalcium phosphate with
crystallites which have at least one size or dimension in the
nanometer range, in particular in a range from 0.1 nm to 500 nm,
preferably 0.1 nm to 100 nm. The at least one size or dimension can
be the length and/or width (thickness or height) and/or the
diameter, especially the average diameter, of the crystallites.
[0120] Furthermore, the tricalcium phosphate can be present in an
amorphous form. This enables particularly good and/or rapid
absorption to be achieved.
[0121] Furthermore, the tricalcium phosphate can be a phase-pure
tricalcium phosphate. The term "phase-pure" shall be understood to
mean in particular phase-pure in the sense of a relevant
regulation, preferably according to ASTM F1088.
[0122] Furthermore, the tricalcium phosphate can have a porosity of
less than 50%, in particular less than 20%, preferably less than
15%.
[0123] Furthermore, the tricalcium phosphate cannot be porous.
[0124] Furthermore, the tricalcium phosphate can be a naturally
occurring tricalcium phosphate or a tricalcium phosphate obtained
from natural tricalcium phosphate.
[0125] Furthermore, the tricalcium phosphate can be a synthetic,
i.e. man-made or artificial, tricalcium phosphate.
[0126] The tricalcium phosphate is preferably selected from the
group consisting of alpha-tricalcium phosphate (.alpha.-TCP),
beta-tricalcium phosphate (.beta.-TCP) and a mixture of
alpha-tricalcium phosphate and beta-tricalcium phosphate.
[0127] In particular, the tricalcium phosphate can be sintered
tricalcium phosphate.
[0128] The sintered tricalcium phosphate is preferably selected
from the group consisting of sintered alpha-tricalcium phosphate,
sintered beta-tricalcium phosphate and a mixture of sintered
alpha-tricalcium phosphate and sintered beta-tricalcium
phosphate.
[0129] Furthermore, the osteoconductive supporting bodies can
comprise apatite and tricalcium phosphate or consist of apatite and
tricalcium phosphate. The osteoconductive supporting bodies
preferably comprise hydroxylapatite and beta-tricalcium phosphate
or consist of hydroxylapatite and beta-tricalcium phosphate. With
regard to further features and advantages of the apatite and the
tricalcium phosphate, reference is made to the preceding
statements.
[0130] In a further configuration of the invention, the
osteoconductive supporting bodies have a roughened surface. This
allows bone tissue growth or adherence, in particular to an
osteoconductive lead structure formed by the supporting body, to be
optimized. For the purposes of the present invention, the term
"roughening" shall be understood to mean in particular that a
roughness of the surface is increased after the supporting bodies
have been shaped, in particular in a manufacturing step provided
therefor. Roughening can be done, for example, by etching, in
particular using phosphoric acid. The supporting bodies preferably
have a roughened surface, the roughness of which is increased by at
least 10% compared to a non-roughened supporting body surface. The
term "roughness" shall be understood to mean in particular an
unevenness in the surface of the osteoconductive supporting
bodies.
[0131] In a further configuration of the invention, the supporting
bodies are produced by an additive manufacturing process.
[0132] In a further configuration of the invention, the supporting
bodies comprise calcium phosphate cement or consist of calcium
phosphate cement. The calcium phosphate cement can be, in
particular, a calcium phosphate cement which is subjected to a
pressure, preferably absolute pressure, of at least 2 bar before
complete curing. In this way, the porosity can be reduced with
particular advantage.
[0133] In a further configuration of the invention, the
osteoconductive supporting bodies are integrally connected to one
another, in particular glued to one another.
[0134] In a further configuration of the invention, the
osteoconductive supporting bodies are coated with a binder. The
binder is preferably a binder which can be dissolved by heat or a
solvent such as N-methyl-pyrrolidone (NMP). By using such a binder,
it is possible to connect the osteoconductive supporting bodies to
one another by heating and subsequent cooling or by adding a
solvent. The binder can be, for example, polylactide and/or
poly(lactide-co-glycolide) (PLGA).
[0135] In a further configuration of the invention, the
osteoconductive supporting bodies are designed such that they favor
compacting, in particular impacting, of the supporting bodies, for
example by a suitable instrument such as an impactor. With regard
to correspondingly suitable configurations of the osteoconductive
supporting bodies, reference is made to the following
statements.
[0136] In a further configuration of the invention, the
osteoconductive supporting bodies are regularly shaped, i.e. are
present as molded bodies. For the purposes of the present
invention, the term "regularly shaped" or "molded body" shall be
understood to mean in particular the shapes described below.
[0137] The osteoconductive supporting bodies, in particular molded
bodies, can have a polygonal cross section. For example, the
osteoconductive supporting bodies, in particular molded bodies, can
have a triangular, square, rectangular, pentagonal, hexagonal,
seven-cornered, octagonal, nine-corner, decagonal or star-shaped
cross section.
[0138] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can have different cross sections. With
regard to possible cross sections, reference is made to the cross
sections mentioned in the previous paragraph.
[0139] The osteoconductive supporting bodies, in particular molded
bodies, can furthermore be polyhedral, in particular cuboid,
cube-shaped, tetrahedral, prism-shaped, pyramid-shaped, truncated
pyramid-shaped or rod-shaped.
[0140] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can have different polyhedron shapes. In
other words, the osteoconductive supporting bodies, in particular
molded bodies, can be present in different polyhedron shapes. With
regard to possible polyhedron shapes, reference is made to the
previous paragraph.
[0141] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can have a cornerless cross section. For
example, the structural elements can have an oval-shaped, in
particular circular or elliptical, cross section.
[0142] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can be non-polyhedral, in particular
spherical, conical, frustoconical, annular, toroidal or
circular-cylindrical.
[0143] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can have different non-polyhedron shapes.
In other words, the osteoconductive supporting bodies, in
particular molded bodies, can be present in different
non-polyhedron shapes. With regard to possible non-polyhedron
shapes, reference is made to the previous paragraph.
[0144] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can be in the form of oligopods, i.e.
oligopod-shaped.
[0145] The oligopods can in particular have legs that are conical
and in particular rotationally symmetrical. The legs can have a
cone angle of 5.degree. to 25.degree., in particular 7.degree. to
15.degree..
[0146] Furthermore, the oligopods can have legs with a length of
0.5 mm to 5 mm, in particular 1.5 mm to 2.5 mm.
[0147] Furthermore, the oligopods can have legs with an average
diameter of 0.2 mm to 3 mm, in particular 0.3 mm to 0.7 mm.
[0148] The oligopods can also be selected from the group consisting
of tripods, tetrapods, pentapods, hexapods, heptapods, octapods or
mixtures thereof.
[0149] According to the invention, it can be particularly preferred
if the osteoconductive supporting bodies are designed in a tetrapod
shape. A tetrapod-shaped design allows a particularly effective
mutual interlocking of the osteoconductive supporting bodies.
[0150] Furthermore, the osteoconductive supporting bodies, in
particular molded bodies, can comprise elongated structural
elements. In particular, the osteoconductive supporting bodies, in
particular molded bodies, can be composed of elongated structural
elements.
[0151] For the purposes of the present invention, the term
"elongated structural elements" shall be understood to mean
structural elements with a length-width ratio or length-diameter
ratio>(pronounced: greater) 1.
[0152] The osteoconductive supporting bodies, in particular molded
bodies, can preferably comprise elongated and straight structural
elements. The osteoconductive supporting bodies, in particular
molded bodies, are preferably composed of elongated and straight
structural elements.
[0153] The elongated structural elements are preferably polyhedral,
in particular cuboid, cube-shaped, prism-shaped, pyramid-shaped,
truncated pyramid-shaped or rod-shaped. In other words, the
structural elements of each osteoconductive supporting body, in
particular molded body, preferably form a polyhedral, in particular
cuboid, cube-shaped, prism-shaped, pyramid-shaped, truncated
pyramid-shaped or rod-shaped arrangement.
[0154] The elongated structural elements can have a length of 0.4
mm to 5 mm, in particular 0.8 mm to 4.5 mm, preferably 1 mm to 4
mm.
[0155] Furthermore, the elongated structural elements can have a
width, in particular an average width, or a diameter, in particular
an average diameter, of 0.4 mm to 5 mm, in particular 0.8 mm to 4.5
mm, preferably 1 mm to 4 mm.
[0156] Furthermore, the elongated structural elements can have a
cornerless cross section. For example, the structural elements can
have an oval-shaped, in particular circular or elliptical, cross
section.
[0157] Alternatively, the structural elements can have a polygonal
cross section. For example, the structural elements can have a
triangular, square, rectangular, pentagonal, hexagonal, heptagonal,
octagonal, nonagonal, decagonal or star-shaped cross section.
[0158] The advantage of osteoconductive supporting bodies, in
particular in the form of molded bodies, with elongated and in
particular straight structural elements, in particular as described
so far, is that the mutual arrangement of the structural elements
per supporting body, in particular molded bodies, can create
additional void volume, which improves the osteoconductive
properties of the supporting body, in particular the molded body,
and therefore the implant can be improved additionally. In
particular, the pore size (absolute void volume) and the porosity
(ratio of material volume to void volume) of human or animal bone
can be optimally simulated.
[0159] In a further configuration of the invention, the
osteoconductive supporting bodies are irregularly shaped.
[0160] The osteoconductive supporting bodies can be in particular
in particulate form, i.e. in the form of particles.
[0161] The osteoconductive supporting bodies are preferably
designed as broken material, in particular as bulk material,
preferably granules.
[0162] For the purposes of the present invention, the term "bulk
material" shall be understood to mean a particulate material, i.e.
a material in the form of particles, the particles of which have at
least one size or dimension smaller than 7 mm, preferably in a size
range from 0.5 mm to 5 mm. With the at least one size or dimension
can be the height and/or length and/or width (thickness) and/or the
diameter, in particular average diameter, of the particles. For the
purposes of the present invention, the term "granulate" shall be
understood to mean an irregularly shaped, particulate material, in
particular a broken and/or sieved material.
[0163] Furthermore, the osteoconductive supporting body can be
designed as a non-broken material. For example, the osteoconductive
supporting bodies can be designed as an additively manufactured
material, i.e. as a material which is produced by an additive
manufacturing process.
[0164] For the purposes of the present invention, the term
"additive manufacturing process" shall be understood as a casting
process for the rapid and cost-effective production of models,
samples, prototypes, tools and end products, the manufacturing
being carried out directly on the basis of computer-internal data
models (usually transferred via an STL interface) from formless
(for example liquids, gels, pastes or powders) and shape-neutral
(for example band-shaped, wire-shaped or leaf-shaped) material by
means of chemical and/or physical processes. Such a process can
also be referred to as a generative manufacturing process.
[0165] The osteoconductive supporting bodies preferably have at
least one size or dimension in a size range from 0.5 mm to 5 mm, in
particular 0.1 mm to 3 mm, preferably 1 mm to 2 mm. The at least
one size or dimension can be the height and/or width (thickness)
and/or length and/or the diameter, in particular average diameter,
of the osteoconductive supporting bodies.
[0166] In a further configuration of the invention, the
osteoconductive supporting bodies are designed to be movable
relative to one another, in particular displaceable relative to one
another.
[0167] In a further configuration of the invention, the
osteoconductive supporting bodies are designed so that they can be
impacted, i.e. mutually clamped or mutually wedged.
[0168] In a further configuration of the invention, the
osteoconductive supporting bodies are present in an impacted form,
i.e. mutually clamped or mutually wedged.
[0169] In a further configuration of the invention, the
osteoconductive supporting bodies can, preferably by means of
impacting, be converted into a three-dimensional structure or
matrix, in particular having voids and/or spaces, or are present in
such a structure or matrix. For the purposes of the present
invention such a structure or matrix can also be referred to as an
osteoconductive lead structure or osteoconductive lead matrix.
[0170] The voids and/or spaces between the structure or matrix can
have a diameter, in particular average diameter, of 0.1 mm to 1.2
mm, in particular 0.2 mm to 1 mm, preferably 0.3 mm to 0.8 mm.
[0171] Furthermore, with a particular advantage the structure or
matrix can comprise a void volume and/or space volume of 5% to 95%,
in particular 10% to 80%, preferably 20% to 70%. Such a void volume
and/or space volume optimally reflects the pore volume of a human
or animal cancellous bone and brings about an improvement in the
osteoconductivity of the implant and in particular in the
biological reconstruction of an osseous defect.
[0172] The voids and/or spaces between the structure or matrix are
interconnected at least in part. In this way, the structure or the
matrix optimally reflects the porosity, in particular
interconnecting porosity, of the human or animal cancellous bone.
In this way, ingrowth of bone tissue into a defective bone area and
in particular growth of a defective bone area with vital bone
tissue can also be stimulated and/or enhanced with particular
advantage. This also contributes to an improvement in the
osteoconductive properties of the implant and in particular the
biological reconstruction of a bone defect.
[0173] It is further preferred if the structure or matrix has a
modulus of elasticity, also referred to as Young's modulus, of 10
MPa to 10 GPa, in particular 50 MPa to 1 GPa, preferably 80 MPa to
350 MPa. For the purposes of the present invention the term
"modulus of elasticity (Young's modulus)" shall be understood to
mean the modulus of elasticity. The value of the modulus of
elasticity is greater, the more resistance a material opposes to
its elastic deformation. A body made of a material with a high
modulus of elasticity is therefore stiffer than a body of the same
configuration (same geometric dimension), which consists of a
material with a low modulus of elasticity. The values for the
modulus of elasticity disclosed in this paragraph optimally reflect
the corresponding values of cancellous bone, which has a modulus of
elasticity of 100 MPa to 1,000 MPa.
[0174] Due to the low Young's modulus described in the previous
paragraph, the osteoconductive supporting bodies can be loaded
mechanically in a uniform manner, i.e. homogeneous. In particular,
the voids and/or spaces of the structure or matrix described in the
previous paragraphs can also be mechanically loaded. By uniform or
homogeneous mechanical loading of the osteoconductive supporting
body and thus the implant, bone formation, in particular new bone
formation, can again be achieved with particular advantage within
an entire osseous defect area.
[0175] In a further configuration of the invention, the
osteoconductive supporting bodies have openings or depressions, in
particular through openings. As a result, the supporting bodies can
be (more easily) compressed, in particular deformed, under load.
Corresponding loads leading to compression of the supporting body
can occur, for example, when a force is applied by a user,
preferably a surgeon. As a result, compaction, in particular
impaction, of the osteoconductive supporting bodies can be
additionally improved, which in turn results in improved
load-bearing properties of the implant.
[0176] The openings or depressions can be selected from the group
consisting of holes, pores, tears, slots, cracks, gaps, notches and
combinations of at least two of the openings or depressions
mentioned.
[0177] The openings or depressions can also be geometrically
defined or undefined openings or depressions.
[0178] In particular, the openings or depressions can have an oval,
in particular circular or elliptical, cross section. Alternatively
or in combination, the openings or depressions can have a
polygonal, in particular triangular, square, rectangular,
pentagonal, hexagonal, heptagonal, octagonal, nonagonal, decagonal
or star-shaped cross section.
[0179] The openings or depressions can have a diameter of 0.01 mm
to 5 mm, in particular 0.1 mm to 4 mm, preferably 0.5 mm to 3 mm.
Such diameters can be preferred if the openings are designed as
through openings through which, as will be explained in more detail
below, a tension element is to be passed for the purpose of
connecting or lashing the osteoconductive supporting bodies
together.
[0180] Alternatively, the openings or depressions can have a
diameter, in particular average diameter, of 60 .mu.m to 500 .mu.m,
preferably 100 .mu.m to 400 .mu.m. Such diameters are preferred if
the openings or depressions are designed as pores.
[0181] Preferably, the openings or depressions are pores. In other
words, the osteoconductive supporting bodies can preferably be
designed with open pores. In particular, the osteoconductive
supporting bodies can have an interconnecting porosity.
[0182] In a further configuration of the invention, the
osteoconductive supporting bodies comprise fibers. The fibers can
in principle be short and/or long fibers.
[0183] For the purposes of the present invention, the term "short
fibers" shall be understood to mean fibers with a length of 0.01 mm
to 1 mm, in particular 0.1 mm to 1 mm, preferably 0.5 mm to 1
mm.
[0184] For the purposes of the present invention, the term "long
fibers" shall be understood to mean fibers with a
length>(pronounced: greater) 1 mm.
[0185] The short and/or long fibers can be metal fibers and/or
polymer fibers.
[0186] In a further configuration of the invention, the implant
also has a tension element. The tension element is preferably
designed to be passed through through openings in the
osteoconductive supporting body. This makes it particularly
advantageously possible to connect the osteoconductive supporting
bodies to one another or to lash them down. The tension element is
therefore expediently an elongated tension element.
[0187] The tension element is preferably a textile, in particular
thread-like, tension element. For example, the tension element can
be a thread (tension thread), in particular a monofilament,
pseudomonofilament or multifilament thread. In particular, the
tension element can be a surgical suture thread.
[0188] Furthermore, the tension element can be a textile fabric, in
particular in the form of a knitted, braided, crocheted, scrim,
fleece or nonwoven fabric. The tension element is preferably a
mesh, in particular a small-pore mesh, preferably a hernia mesh. By
integrating the osteoconductive supporting bodies in a mesh-shaped
tension element, a regular arrangement of the supporting bodies can
be achieved.
[0189] Alternatively, the tension element can be a wire (pulling
wire).
[0190] The use of a tension element enables the osteoconductive
supporting body to be fastened or lashed down with particular
advantage, as a result of which an immediate increase in the
strength of the osteoconductive supporting bodies with one another
and thus of the implant can be achieved. Such an increase in
strength reduces the risk that a scaffold structure formed by the
supporting bodies will break apart after a brittle fracture.
Furthermore, by attaching or lashing down the osteoconductive
supporting body with a particular advantage an open-pore scaffold
structure can be realized. Furthermore, there is the possibility
that a tension element-supporting body unit (or possibly a
plurality of tension element-supporting body units) can be fixed to
a further implant and/or to a bone and can thereby be fixed in
place. The tensile element-supporting body unit (or tensile
element-supporting body units) can be pressed onto a further
implant, for example, a freshened bone, by attachment. This enables
an optimal connection to the bone and the resulting pressure on the
bone promotes bone growth. The force transfer at the bone defect is
preferably carried out by the implant. This eliminates the pressure
stimulus that stimulates the bone to build bone (stress shielding).
This pressure stimulus can be built up by the tension
element-supporting body unit(s) which are under pressure to the
bone.
[0191] The tension element can comprise a polymer and/or metal or
consist of a polymer and/or metal. The polymer can be, for example,
polyethylene or polypropylene, and the metal can be, for example,
titanium or tantalum.
[0192] In a further configuration of the invention, the
osteoconductive supporting bodies are designed such that they can
be connected to one another in a form-fitting, force-fitting and/or
firmly bonded manner. The osteoconductive supporting bodies are
preferably designed in such a way that they can be connected to one
another in a form-fitting manner. For example, the supporting
bodies can be designed such that they can be connected to one
another via a plug-in system or in the manner of a plug-in system.
The plug-in system can be based on a so-called pin-hole principle,
preferably with an undercut for better anchoring of the
osteoconductive supporting bodies. For this purpose, part of the
osteoconductive supporting bodies can be provided with pins and
another part of the osteoconductive supporting bodies can be
provided with suitable pin holes or slots.
[0193] In a further configuration of the invention, the
osteoconductive supporting bodies are connected to one another in a
form-fitting, force-fitting and/or firmly bonded manner. The
supporting bodies are preferably connected to one another in a
form-fitting manner. For example, the osteoconductive supporting
bodies can be connected to one another via a plug-in system or in
the manner of a plug-in system. With regard to further features and
advantages of the plug-in system, reference is made to the previous
paragraph.
[0194] In a further configuration of the invention, the
osteoconductive supporting bodies are designed such that they can
be connected to another implant in a form-fitting, force-fitting
and/or firmly bonded manner. The supporting bodies are preferably
designed in such a way that they can be connected to another
implant in a form-fitting manner. For example, the supporting
bodies can be designed such that they can be connected to an
implant via a plug-in system or in the manner of a plug-in system.
The plug-in system can be based on a so-called pin-hole principle.
For this purpose, the supporting bodies can be provided with a pin
and the other implant can have complementary pin holes or slots.
The reverse conditions can also be possible according to the
invention.
[0195] In a further configuration of the invention, the
osteoconductive supporting bodies are connected to one another via
elongated connecting elements. For this purpose, the connecting
elements preferably protrude into recesses or openings in the
supporting bodies. With regard to possible configurations of the
recesses or openings of the supporting bodies, reference is made to
the previous statements.
[0196] In a further configuration of the invention, the
osteoconductive supporting bodies have a proportion of 10% by
weight to 95% by weight, in particular 20% by weight to 90% by
weight, preferably 30% by weight to 70% by weight, based on the
total weight of the implant.
[0197] In a further configuration of the invention, the implant is
a bone replacement material.
[0198] According to a second aspect, the invention relates to a
kit, preferably for the treatment and/or biological reconstruction,
in particular lining and/or sealing and/or relining and/or at least
partially filling, a bone defect.
[0199] The kit has the following components, spatially separated
from one another: [0200] osteoconductive supporting bodies, and
[0201] a sheath for the osteoconductive supporting bodies.
[0202] The kit is characterized in particular by the fact that the
sheath comprises a sheath material or consists of a sheath material
which is soluble in water or in a water-containing liquid.
[0203] The surgical kit can furthermore comprise at least one
further component which is selected from the group consisting of
fastening elements, artificial joint socket such as an artificial
hip joint socket, further biological and/or artificial bone
replacement material, tissue adhesive, a film that is not
degradable in vivo or is not absorbable in vivo, a mesh that is not
degradable in vivo or is not absorbable in vivo, metallic
augmentation material, a fleece that is not degradable in vivo or a
fleece that is not absorbable in vivo, a nonwoven fabric that is
not degradable in vivo or a nonwoven fabric that is not absorbable
in vivo, metallic, bendable or non-bendable lattice structure, bone
cement, growth factors and one or more instruments for applying a
joint socket and/or a supporting material.
[0204] The fastening elements can in particular be bone screws or
nails.
[0205] The tissue adhesive can in particular be a curable adhesive
composition based on cyanoacrylate monomers, in particular
n-butyl-2-cyanoacrylate monomers. Such a tissue adhesive is
commercially available, for example, under the trademark
Histoacryl.RTM..
[0206] By means of the film, mesh, fleece, nonwoven that are not
degradable in vivo or not absorbable in vivo mentioned in
connection with another kit component, or a combination thereof, in
particular a composite structure, it is advantageously possible to
line an open bone defect, in particular an open acetabular defect,
as a result of which the prerequisites for the treatment and/or
biological reconstruction of a closed bone defect, in particular a
closed acetabular defect, can be created.
[0207] With regard to further features and advantages of the
surgical kit, reference is made in full to the statements made for
the purposes of the first aspect of the invention in order to avoid
repetitions. The statements made there in particular with regard to
the sheath, the sheath material and the osteoconductive supporting
bodies also apply (analogously) to the surgical kit according to
the second aspect of the invention.
[0208] According to a third aspect, the invention relates to a
sheath for osteoconductive supporting bodies. The sheath comprises
a sheath material or consists of a sheath material which is soluble
in water or in a water-containing liquid.
[0209] With regard to further features and advantages of the
sheath, reference is made in full to the statements made for the
purposes of the first aspect of the invention in order to avoid
unnecessary repetitions. The statements made there in particular
with regard to the sheath, the sheath material and the
osteoconductive supporting body also apply (analogously) to the
sheath according to the third aspect of the invention.
[0210] According to a fourth aspect, the invention relates to the
use of a material that is soluble in water or in a water-containing
liquid for sheathing osteoconductive supporting bodies.
[0211] With regard to a suitable material soluble in water or in a
water-containing liquid, reference is made to the soluble sheath
materials disclosed in the first aspect of the invention. The
soluble sheath materials described there can also be considered as
materials for the use according to the fourth aspect of the
invention.
[0212] With regard to further features and advantages of the use,
reference is made in full to the statements made for the purposes
of the first aspect of the invention in order to avoid unnecessary
repetitions. The statements made there in particular with regard to
the sheath and the osteoconductive supporting bodies also apply
(analogously) to the use according to the fourth aspect of the
invention.
[0213] According to a fifth aspect, the invention relates to a
method for the treatment and/or biological reconstruction, in
particular lining and/or sealing and/or relining and/or at least
partially filling, a bone defect.
[0214] The bone defect is preferably an acetabular defect, in
particular a closed or open acetabular defect.
[0215] The method comprises the following step: [0216] Placing an
implant according to the first aspect of the invention in the bone
defect.
[0217] In a configuration of the invention, the method also
comprises the following step: [0218] Loading the placed implant by
means of an impactor, i.e. a surgical instrument for compacting, in
particular impacting, the osteoconductive supporting bodies.
[0219] In a further configuration of the invention, the method also
comprises the following step: [0220] Applying a bone cement to the
placed, in particular loaded, implant.
[0221] In a further configuration of the invention, the method also
comprises the following step: [0222] Applying an artificial joint
socket, in particular an artificial hip joint socket, to the sheath
and optionally fixing/attaching the artificial joint socket, in
particular an artificial hip joint socket, to the sheath.
[0223] In a further configuration of the invention, the method also
comprises the following step: [0224] Attaching the artificial joint
socket, in particular an artificial hip joint socket, to a bone,
preferably to a bone that at least partially surrounds the bone
defect.
[0225] With regard to further features and advantages of the
method, reference is also made in full to the statements made for
the purposes of the first aspect of the invention in order to avoid
repetition. The statements made there with respect to the implant,
in particular the sheath, the sheath material and the
osteoconductive supporting bodies, also apply (analogously) to the
method according to the fifth aspect of the invention.
DETAILED DESCRIPTION
[0226] Further features and advantages of the invention result from
the following description of preferred embodiments with the aid of
an exemplary embodiment. Features of the invention can be realized
individually or in combination with one another. The exemplary
embodiments described below serve to further explain the invention
without limiting it thereto.
Exemplary Embodiment
[0227] 1. Materials:
[0228] Carboxymethyl cellulose (Tylopur C), polyvinyl alcohol
(Mowiol 56-98, high molar), polyvinyl alcohol (Mowiol 4-98, low
molar), water for injections (WVI).
[0229] 2. Execution:
[0230] First, a 20% low molar PVA solution and a 20% high molar PVA
solution were made in a Schott flask. For this purpose, 20 g of low
molecular weight polyvinyl alcohol and 80 g of water for injection
as well as 20 g of high molecular weight polyvinyl alcohol and 80 g
of water for injection were filled into separate Schott flasks. The
two mixtures were then stored in a warming cabinet at 95.degree. C.
for 24 hours until they were completely dissolved. Then a 3%
carboxymethyl cellulose solution (3 g sodium carboxymethyl
cellulose+97 g water for injection) was prepared in a laboratory
mixer (laboratory mixer model ESCO type EL 10) or homogenizer under
vacuum (-0.8 bar) at 35.degree. C. and for a mixing time of about 3
to 4 hours.
[0231] A mixture of the low-molar PVA solution and the high-molar
PVA solution, a mixture of the low-molar PVA solution and the
carboxymethyl cellulose solution and a mixture of the high-molar
PVA solution and the carboxymethyl cellulose were then prepared.
These mixtures were each prepared using the laboratory mixer or
homogenizer mentioned above (maximum temperature 35.degree. C.,
vacuum -0.8 bar, mixing time at least 2 hours).
[0232] The mixtures prepared were then formed into a film with the
aid of a squeegee using a laboratory dryer and fixer (Mathis type
LTF 143691) (at approx. 55.degree. C. to 60.degree. C. and during a
drying time of approx. 25 minutes).
[0233] The thickness of the films was 38 .mu.m to 45 .mu.m. The
films dissolved in water within 20 s to 40 s.
[0234] Depending on the setting of the gap size, films could be
made in different thicknesses. The thicker the films, the more
slowly they dissolve in water.
[0235] Films prepared with a thickness of 50 .mu.m to 65 .mu.m
dissolved in water within approx. 3 minutes to 5 minutes.
[0236] Using a bar welder the films prepared could be successfully
welded to form a small bag, which was previously filled with
osteoconductive supporting bodies.
[0237] As an alternative to a welding process, it is conceivable to
seal the foils by means of a tissue adhesive, such as, for example,
a tissue adhesive based on n-butyl-2-cyanoacrylate monomers sold
under the registered trademark Histoacryl.RTM..
* * * * *